Nancy Killefer’s withdrawal came after the Obama team spoke with people on the Hill, and came to believe the Senate would rake her over the coals as the third Obama nominee with a tax issue.

(CNN) - A senior administration official says the tax issues surrounding former chief performance officer nominee Nancy Killefer are "a little more complicated" than some reports have suggested.

There are actually a few tax issues - all in equally small amounts, all related to household help. Killefer’s withdrawal came after the Obama team spoke with people on the Hill, and came to believe the Senate would rake her over the coals as the third Obama nominee with a tax issue.

This official says the vetting team was aware of all Killefer’s tax issues, and that she was immediately forthcoming about them. Going back to the fall, the transition had decided they wanted her for this role when they unveiled the economic team, but held off on announcing her while they determined if they were comfortable with her tax issues. They decided they were, and announced Killefer about two weeks after the rest of the team.

The decision to have her withdraw has built over last two weeks in light of similar controversy swirling around Treasury Secretary Timothy Geithner during his confirmation, and their knowledge of the growing problems surrounding Tom Daschle’s nomination. Killefer, a McKinsey executive, never formally resigned - so she still has a job there to return to.